Variable speed power transmission



Oct. 3, 1950 1.. E. SHAW 2, 75

VARIABLE SPEED POWER TRANSMISSION Filed Oct. 50, 1946 6 Sheets-Sheet 1 LOUIS E SHAW INVENTOR.

d'i iw-u L. E. SHAW.

VARIABLE SPEED Po'wER TRANSMISSION Oct. 3,. 1950 Filed 001;; 30, 1946 6 Sheets-Shet 2 LOUIS E. SHAW INVENTOR.

Oct. 3, 1950 L. E..SHAW

VARIABLE SPEED POWER TRANSMISSION Filed Oat; 30., 1.946

6 Sheets-Sheet 3 FIG-J3 FIG-.IZ

FIGJO INVENTOR. BY 7 LOUIS E.SHAW

I F-W 1 Oct. 3, 1950 l... E. s w 2,524,575

VARIABLE SPEED POWER TRANSMISSION Filed Oct. 50, 1946 6 Sheets-Sheet 4 FIG. 20

LOUIS E.SHAW

INVENTOR. BY i 7' Oct. 3, 1950 E. SHAW VARIABLE SPEED 1 0mm TRANSMISSION 6 Sheets-Sheet 5 Filed Oct. so, 1946 FIG. l5

FIG. l7

FIG-.16

LOUIS E.SHAW

I N VEN TOR.

FIG-J9 Oct. 3, 1950 Filed 0011'. 30, 1946 L. E. SHAW 2,524,575

VARIABLE SPEED POWER TRANSMISSION 6 Sheets-Sheet 6 BELT WIDTH coflsTAu'r, 0.975

FIG. 22

LOUIS E. S HAW INVENTOR.

i atented Oct- 3, 1950 UNITED STATES PATENT OFFICE 2,524,575 r I VARIABLE srEEn rowan 'cu'musivn'ssiou Louis Eaton shew, Newark, N.- J. Application October 30,1946, serialfiofltijifie This invention relates to variable speed power transmissions, and more particularly to a variable pitch, single 'or multiple-groove V-type sheave and the mechanism by means of which its pitch diameter may be varied while in operation.

An object of the present invention is the provision of a multiple belt variable speed transmission mechanism wherein the sheaves are mounted upon driving and driven shafts having fixed axes in which a great range of speed variations is provided without requiring movement of the driving shaft and its driving motor and wherein the pitch diameters of the driving and driven sheave or sheavesare varied inversely without sidewise shifting of the belts with the consequent excessive wear, friction and deteriorating heat action on the belts.

Another object of the present invention is to provide .a variable speed power transmission as specified wherein the side thrust of the belts on variousv parts of the mechanism is materially reduced over that in well known transmission mechanisms of this type.

A further object of the invention is to provide in a variable speed transmission a structure which will permit removal or replacement of the driving belts without requiring dismantling of the mechanism. V

A still further object of the present invention is to provide a novel construction of sheave,

wherein the flanges of the sheaves are formed integrally with di itated sleeves that intermesh in pairs and bear directly on the shaft, with the sleeves of one of the flanges of each co-operating pair keyed loosely to the shaft to prevent relative rotation but permit free axial shifting while the sleeves of the other flanges are not keyed to the shaft but are driven from the keyed sleeves through the digitations.

With these and other objects in view, as may appear from the accompanying specification, the invention consists of various features of construction and combination of parts, which will be first described in connection with the accompanying drawings, showing a variable speed power transmission of a preferred form embodying the invention; and the'features forming the invention will be specifically pointed out in the claims;

In the drawings:

Figure 1 is a top'plan of the improved variable speed drive.

v Figure 2 is a vertical section through the variable speed drive taken onthe line 2--2 of Figure 1. 1

Figure 3 is alongitudinal section throughjthe :input or driving" assembly of the variable speed drive and taken on the line 3-3 of Figure 2.

Figure 4- is a viewpartly in longitudinal sectionand partlyin" elevation or the output or "or eisure 12 Claims. (01. 74 4.30.17)

driven assembly of the drive and taken on line of Figure 1.

Figure 5 is a cross section through the input or driving assembly or the drive and taken on the line 5+5 or Figureii.

Figure 6 is adeta'il cross-section through the drivingor input shaft taken on the line 6-6 of Figure 3. v r

Figure 7 is a diagrammatic view partly in sec"- tiflon showing the shifting cam for shifting the sheave sections.- I

Figure 8 is an elevation of the first of the sheave flang'es in the assembly.

F'guree is a cross-section taken on line 9-9' Figure '10 is an elevation of the motivating sheave flange. I v I Figure 11 is a cross-sectionthroug'h the mou-' vating shave flange andtaken on line I|-ll of FigurlOL j. g

Figure 12 is an elevat'io'n of an intermediate sheavejilange of the assembly. V

Figure 13'isa cross-section taken on line l3-l3 6f Eis e'lz.

Figure 14' is an elevation of one of the intermediate sheave flanges of the assembly.

Figure 15 is'a cross-section taken on line l5-l 5 er Figure 14. q t

Figure I6 is an elevation of another of the intermediate sheave flanges of the assembly.

Figure 17 is a cross-section on line l1-Il of Figure 16.

Figure 18jis side; elevation of the last sheave flange in the assembly.

Figure 19 is a cross-section on the line l9'-l .i

of Figure 18. I Figure 20 is'an elevation of an eccentric ad'- lusting cylinder employed in the drive tofacilit'ate the removal or replacement of the belts.

I Figure 21 is a section taken on the line 2l'-2l f l fi ur 2Q Figure Z'Zfisa diagrammatic view showing the variancesof pitch diameters of a pair of sheaves coupled in the drive for inverse operation on fixed axial centers; g v

The variable speed multiple belt drive of the present invention is of the type wherein sheaves are used in pairs on shafts having fixed centers; with the pitch diameters of the two sheaves (one a driving sheave and the other a driven sheave) varied inversely thereby providing a' relatively great speed range. Also in the present invention the pairs of sheaves etc. are mounted} in ahousing' forming a complete variable speed power-transmission;

Before giving a specific description of the present invention, it is pointed out, for purposes o fclearer understanding of the invention, that I whenever twovariable pitch sheaves, coupled for inverse operation are mounted on fixed This is clearly shown in Figure 22 of the drawings. In this Figure 22 the belt is shown in full line passing over each sheave of the pair at a radius of 2.8" and by broken lines at other radii. In variation of the pitch diameters of the two sheaves it will be noted that whereas the radius of the left hand sheave, namely the sheave A increases by increments of 0.2" the corresponding increments of the right hand sheave B are not only greater but increasingly greater as the radius is reduced.

Without going into details of the calculations necessary to prove the above, starting from the 121 point shown in solid line in Figure 22, if the flanges of the sheave A are moved closer together until the belt runs thereon at a radius' of 3.6 (a radial movement outward of 0.8), it will be necessary to separate or spread the flanges of the sheave B until the beltruns thereon at a radius of 1.9075 (a radial movement inward of 0.8925).

The mechanism hereinafter described specifically in connection with the drawingsprovides for this relative shifting of the flanges and since all of the flanges of the sheaves of the drive of the present invention are shiftable, there will be no sidewise shifting of the belts as occurs in variable speed drives wherein only one set of the flanges of either the driving or sheaves'are shiftable, and further in the present drive mechanism the thrust against the bearings and threaded adjusting members of the drive is greatly reduced through the introduction of leverage between the speed adjusting means and the sheave flanges in comparison with those drives in which there is no such leverage.

Specifically describing the invention in connection with the accompanying'drawings the improved variable speed drive comprises an input or driving assembly I and an output or driven assembly 2, the driving or input shaft 3 and the driven or output shaft 4 of which'assemblies are parallel and mounted in the housing 5 to rotate on fixed axis during operation of the drive.

The power input or driving assembly I includes the driving shaft 3 which is driven from any suitable prime mover (not shown) and which is rotatabl carried by bearings 6 and I, mounted in the inner cylinder 9 of the eccentric cylinder II], the purpose of which will be hereinafter described.

The shaft 3 has the sheave forming flanges I2, I3, I l, l5, I6 and I1 mounted thereon and arranged in opposed pairs with the angled face I8 of one flange facing the angled face of the adjacent flange to form the substantially V- shaped grooved sheaves over which the belts (not shown) travel.

All of the sheave flanges I2, I3, I I, I5, I6 and I1 have digitated sleeves I9 formed thereon that intermesh in pairs and bear directly on the shaft 3. Each sleeve IS has three digitations 20 thereon and those of the flanges I5, I3, and I! are provided with keyways 2'I which receive keys 22 carried by the" shaft 3 to prevent their rotation relative to the shaft but permit them to be freely shifted along the shaft.

a the output or driven assembly 2.

The keys 22 are undercut for a part of their length as shown at 23 so as to form with the keyways 25, in the shaft, passages for flow of a lubricant which flows from such passages through openings 25 in the keys 22 to lubricate the inner surfaces of the digitated sleeves I9 of the various flanges where they engage the shaft 3. The lubricant is delivered to the passages formed by the keyways 2 and the undercut portions of the keys 22 through radiating passages 26 and a longitudinal passage 21 formed in the shaft 3.

The flanges I2, I 1 and I6 are connected by bolts 28 which are threaded into the flange 16, as shown at 29, and have nuts 36 on their other ends which seat in counterbores 3| formed in the flange I2, while the flanges I3, I5, and H are connected by bolts 32 which are threaded into the flange I3 and have nuts 33 on their other ends which seat in counterbores 34 formed in the flange IT.

The digitations 29 of the sleeve II) of the flange I5 have notches 35 cut in their outer surfaces near their outer ends and one of these notches receives therein the tooth 36 of the two toothed shifting gear .31.

The tooth 38 of the gear 31 engages in a notch formed in the block 39 which is carried by the flange H. The teeth 36 and 38 are disposed diametrically opposite of each other, as is clearly shown in Figure 3 of the drawings so that when the gear 3'! is rotated the flange I1 and the flanges I5 and I3 will move in one direction While the flange I6 and the flanges I4' and I2 will move in the opposite direction. Thus all of the flanges making up the sheaves will move simultaneously with the opposing flanges moving towards or from'each other to vary the pitch diameters of the sheaves formed by the pairs of opposing flanges.

The gear 3'! is mounted upon a stub shaft 40 for limited rotary movement thereon, and it has an arm 4| connected thereto. The arm 4| has a roller 42 rotatably carried by its free end and this roller rides on the inclined outer surface of the cone cam II.

The cone cam II is slidably mounted on the end of the shaft 3 remote from the end to which the prime mover (not shown) is connected and it also is slidably supported by the housing 43 which encloses the major portion of the cone cam II the gear 31 etc., and as clearly shown in Figure 3 of the drawings.

A spider :4 is provided which together with the cone cam II carries the bearing 8 and this spider which is not connected to the cone cam II in any other manner has a threaded bore 45 which threadably receives an adjusting screw 66. The inner end of the adjusting screw 46 is rotatably supported by .a bearing ll which is carried b the shaft 3 in the longitudinal recess 4'8 formed in the end of the shaft 3, thus when the adjusting screw 46 is rotated the cone cam II will be moved longitudinally along the shaft 3.

The adjusting screw 46 has a sprocket 49 mounted on its outer end which is connected by a sprocket chain 50 to the sprocket 5| mounted on the outer end of the adjusting screw 52 of A sprocket 53 engages the chain 50, and this sprocket 53 is brackets 55 and 56 are ingstll and 61 carried by the cylindrical hous 7 hile' in the drawihgs pnly a part of the cone 63 is shown prdtrudingiirom the housing 64 t5 be" understood t at t e output or driven as rnbly includes mechanijsm or elements idenc li i input or driving assembly I to providefor the s rti g r the n -ge 2, l3, I4", 15', I6 and I1 which are embodied in the output assemyiuh 4 rhena ges r21, [3, 14', I5", I6 and n are of the saine construction as the corresponding fla ges 2, I n, m lt, and IT having the same di'g'itated sleeves and operate in the same manner, the opp'oj sed pairs co-"operating to form sheaves which act as a sheave of a' pair driven by a belt with the corresponding sheave of the driving or input element. r

7 To providefdr the varying of the pitch diamters of the airs of eeeperating sheaves of the driving arid 'driveii asseinb es as set out above iii the spe'eifieati'on the eamsdrrae'e 'of the cone ure 7 i t e awings. The angle of incline of the cam surface em, the maximum diameter t feretr to teamm e-1y the median diameter is nter terme titan ah e er a predetermined deree; asst? in Fig re 7, w ne the angle of incliri'of the cam face hem approximately the medianldiameterto the mihiinumdiameter is cut eta difierentahg'le or iess degree, shown as 37 ihFigure 7 x The cutting ""i heeem retrea the angles of different degree, carefully calculatedin accordahee with the jdifie'r'ehe' s in the pitch diameters Qtlth sheaves-er a (fie-operating pair, will provide .for the ahah'ee desired a's set out on page 4 heredflto maintain the belts under the proper handle {ii for rotating a rod Bl on which is mount-' ed a werm 5.8. The worm 58 meshes with the teeth 69 on the perimeter of the eccentric cylinder Ii) sothat when the eiahk handle th s rotated the,

inpiit shaft 3 will rnoved towards or irom the oiitp ii tshaft 4. The braeket {i5 remote from the end inoiinted in the bearings slides freely on the r'odiiii, the latter being held by cotter pin H to the racke 56. I a W When it isde'sired jor necessary to removeor replace thebeltsofjhe drive or any of them, the 1 nd e is, r9iaie in h 'p cti n, which in turn rotatesthe eccentric cylinder Hi to move the shaft 3 towards the shaft 4. The sprocket chain 50 is then removed and the belts (not shown) maythen he slipped ofi? over the m ner ends of the shafts 3 and 4. After the belts have been removed and replaced by others, the

chain 50 is again put in place on the sprockets #19 these enclosed in the housing 43 ofth e and 5| are the erenk handle at heated is mate the shaft 3 away from the shaft 4 as far neeessary to give correct initialtensidh to the-belts. This adjustment also perinits the helps tb' be tight ened from time to time to compensate for any stretching or wearthatrnay have occurred. The threaol arigleof the worm 6B of the teeth 69 is soslight that the sleeve or cylinder l0 will remain locked in any position of adjustment.

It hite uh erst bd that theinvention is not tobe limited to the specific construction or arrangement of parts shown, but that they may be wi en modified within the invention defined by the claims.

What is claimed is:

1. In a variable speed power transmission, a pdwerlihput shaft, a power output shaft, a pluralityof digited sleeves mounted slidably on each of said shafts, sheave forming flanges on said sleeves and arranged in pairs to iorm sheav's on eaeh shaft, the sheave h the input shaft cooperating with corresponding sheaves en the output, shaft, means for loosely keying tine sleeve of each pair of flanges to its shaft for rdtation therewith, the digit'ations on saidkeyed sleeves meshing i the digitations on the non-keyed sleeves where-1 the hon keye'd sleeves and their flanges will be rotated by rotation of the keyed sleeves, means for moving said sleeves and their flanges axially on their shaftsto vary the pitch diam eters 'of the sheaves, said sleeve and flange moving including eperatihg sai cams being movable along the axes of the shaft, means for operating said cams iii unison, the operating surfaces-er said cams being inclined and having the angle of incline from the maximum diameter to approximately the median diameter cut at pr'e:

determined degree and the ngl of incline from approximately the median diameter th the minimum diameter cut at an angle of lesser degree sd that whe'rione cam moves the flanges forming the sheaves on one shaft to increase the pitch diameters of the sheayes the other cam will move the sheave forming flanges of the sheaves on the second shaft to decrease their pitch diameters. ,v

, 2. A variable speed power transmission as claimed in claim 1 embodying bearings for said power input shaft, cylinder eccentrically carry: ing said bearings, and means for rotating said cylinder about its axis to move said power input shaft towards or fromsaid power output shaft.

3;;A variable speed power transmission as claimed in claim 1 wherein the digitations of the sleeves of one of the pairs of flanges on each the power input and power output shafts are provided with notches therein; two toothed gears with theirteeth engaging in said notches, means connected to said gears and said cams for rotating the gear upon movement of the cams to move the sleeves and their flanges axially of the shafts.

4. A variable speed drive as claimed in claim 1 wherein said cam operating means includes an operating spider rotatably connected'to eachof the cams for moving the cams axially, means for moving said spiders, and means connected to said spider moving means for moving the spiders in unison. i

5,. A variable speed drive as claimed in claim 1 wherein the cams are mounted on one end of each shaft; the ends of said shafts upon which said cams are mounted being hollow; and said cam operating means includes feed screws rotatably mounted in the hollow ends of the shafts, spiders mounted on said feed screws, means rotatably connecting said spiders to said cams for moving:

7 the cams axially on the shafts upon rotation of the feed screws.

6. A variable speeddrive as claimed in claim 1 wherein the angled inclined operating surfaces of said cams have their longitudinal lines extending longitudinally of said shaft, cam rollers engaged against said inclined surfaces, pivoted arms carrying said cam rollers, and means connecting said pivoted arms and said sheave flanges for moving the flanges upon movement of the arms.

'7. A variable speed drive as claimed in claim 1 wherein the cams-are mounted on one end of each shaft, the ends of said shafts upon which said cams are mounted being hollow, an operating spider rotatably connected to each of said cams for moving the cams axially along said shafts, means carried by the hollow ends of said shafts for moving said spider, and means connected to said spider-moving means for moving the spiders in unison.

8. A variable speed drive as claimed in claim 1 wherein the cams are mounted on one end of each shaft, the ends of said shafts upon which said cams are mounted being hollow, an operating spider rotatably connected to each of said cams for moving the cams axially along said shafts, means carried by the hollow ends of said shafts for'moving said spider, means connected to said spider-moving means for moving the spiders in unison, the angled inclined operating surfaces of said cams having their longitudinal lines extending longitudinally of said shaft, cam rollers engaged against said inclined surfaces, pivoted arms carrying said cam rollers, and means connecting said pivoted arms and said sheave flanges for moving the flanges upon movement of the arms.

9. A variable speed power transmission including a power input shaft, a power output shaft, a plurality of digited sleeves slidably mounted on each of said shafts, sheave-forming flanges on said sleeves and arranged in pairs to form sheaves on each shaft, the sheaves on the input shaftcooperating with corresponding sheaves on the output shaft, means for keying one sleeve L of each pair of flanges to its shaft for rotation therewith, the digitations on said keyed sleeves meshing with the digitations on the non-keyed sleeves whereby the non-keyed sleeves and their flanges will be rotated by rotation of the keyed sleeves, means for moving said sleeves and their flanges axially on their shafts to vary the pitch diameter of the sheaves including cams slidably mounted for longitudinal movement on said shafts, the operating surfaces of said cams being inclined and having the angle of incline from the maximum diameter to approximately the median diameter cut at a predetemined degree and the angle of incline from approximately the median diameter to the minimum diameter out at an angle of lesser degree, the degrees of the angles of incline of said angles of said lesser degree being regulated relative to the angles of incline of the other surfaces so that upon operation of the cams the pitch diameter of certain of the sheaves would be decreased in greater increments than the pitch diameter of the other sheaves so increased.

10. In a variable speed power transmission, a shaft, a sheave on said shaft comprising a pair of flanges movable towards or from each other to vary the pitch diameter of the sheave, a cam mounted on said shaft, means connecting said cam and flanges to move the flanges upon movement of the cam, the operating surface of said cam being inclined and having the angle of incline from the maximum diameter to approximately the median diameter cut at a predetermined degree and the angle of incline from approximately the median diameter to the minimum diameter cut at an angle of lesser degree, a spider rotatably connected to; said cam,'means for moving said spider longitudinally of said shaft to move said cam longitudinally of said shaft.

, 11. In a variable speed power transmission, a shaft, a sheave on said shaft comprising a pair of flanges movable towards or from each'other to vary the pitch diameter of the sheave, a cam mounted on said shaft, means connecting said cam and flanges to move the flanges upon movement of the cam, the operating surface of said cam being inclined and having the angle of incline from the maximum diameter to approximately the median diameter cut at a predetermined degree and the angle of incline from approximately the median diameter to the minimum diameter cut at an angle of lesser degree, said shaft having one end hollow, a feed screw r0- tatably carried by said hollow end, a spider mounted on said feed screw for longitudinal movement of the spider upon rotation of the feed screw, and means rotatably connecting said spider and said cam.

12. In a variable speed power transmission, a shaft, a sheave on said shaft comprising a pair of flanges movable towards or from each other to vary the pitch diameter of the sheave, a cam mounted on said shaft, means connecting said cam and flanges to move the flanges upon movement of the cam, the operating surface of said cam being inclined and having the angle of incline from the maximum diameter to approximately the median diameter cut at a predetermined degree and the angle of incline from approximately the median diameter cut at an angle of lesser degree, the angled inclined operating surfaces of said cam having its longitudinal lines extending longitudinally of the shaft, said means connecting said cam and flanges to move the flanges including pivoted arms, cam rollers carried by said pivoted arms and engaging the inclined surfaces of said cam, and means connecting said pivotedarms and said sheave flanges.

LOUIS EA'ION SHAW.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS FOREIGN PATENTS Country Number Number Date Great Britain Mar. 12, 1937' 

